Voyage of Darwin’s Beagle S1:E8

One Small Step For Man

The first episode visits Tenerife of Canary Islands and Cape Verde while crossing the Atlantic ocean to Salvador da Bahia in South America. The narration is interlaced with quotes read from Darwin’s The Beagle Diary.

Low Life on the Ladder of God

When Darwin set foot in Rio de Janerio he witnessed the brutality of slavery. Brazil is a melting pot of genetic diversity. All fossil and genetic evidence points that Africa is the home continent where modern Humans originated about 200 thousand years ago. As Humans spread and colonized new continents genetic diversity eroded gradually proportional to the distance away from Africa. Loss of genetic diversity was because of joint effects of two well understood genetic phenomena known as population bottleneck and founding events.

The Last Frontier

Darwin had some damning statements about Fuegans contrasting with his contemporary co-discoverer of the theory of evolution Alfred Russel Wallace who had a huge respect to people he met both in the Amazons and Malay Archipelago. Meeting with savage Fuegans made Darwin thought that Humans are no different from other animals whose actions are constrained by nature.

The Final Countdown

The crew of Stad Amsterdam visits a few of the remaining glaciers on the southern tip of South America and reflects on the geology of Andes mountain range. Reduction in mass balance of glaciers is a worrying trend reported by glaciologists. The episode also covers problems associated with salmon farms in Chili.

The Paradise of Competition

The Galapagos islands has been a pivotal single location where everything came together in Darwin’s mind. The geology of the archipelago and almost every species (Tortoises, iguanas, finches) he observed on each island showed significant variation.

Toolbox of Survival

In Australia the arrival of Europeans profoundly effected the biology of the continent through introduction of non-native species that are reproducing and invading at an unprecedented rate. Australian biologists call it “extinction calamity” since the continent has lost one in ten of its native mammals species in the past 200 years. The effects of climate change is also evident with severe droughts and wild fires. A large fraction of Australian vegetation is serotinous that is adapted to disperse their seeds when triggered by fire. Cane toads are one of the prime example of catastrophic species introduction with unintended consequences. Decades after their intentional release cane toads continue to spread over the continent.

Adapt or Die!

In this leg of the journey in Australia the theme “On the Future of Species” dominates the episode. Darwin absolutely had no clue on how genetic information from parents were transmitted to the offspring and he was perfectly aware of his situation. On the other hand, while he was writing his book battling with hereditary questions, an Augustinian friar with a scientific mind was carrying out his experimental crosses in a monastery which was going to lay the foundations of genetics.